Flexible panel with abutting reaction shoulders under compression



Dec. 13, 1966 G. F BOWDEN ET AL FLEXIBLE PANEL WITH ABUTTING REACTION SHOULDERS UNDER COMPRESSION 2 Sheets-Sheet 1 Filed May 27, 1964 INVENTORS GEORGE F. BOWDEN fP/CHARD c. CAP/5K E v z E z N W (/L A M 1 G. F. BOWDEN ETAL FLEXIBLE PANEL WITH ABUTTING REACTION SHOULDERS UNDER COMPRESSION Dec. 13, 1966 2 Sheets-Sheet Filed May 27, 1964 CAI V mmx A n m 5 NWP MQR w m a WBCJJ/MT 5w. Fr W H m} GP United States Patent 3,291,437 FLEXIBLE PANEL WITH ABUTTING REACTION SHOULDERS UNDER COMPRESSION George F. Bowden, Des Plaines, and Richard C. Capek,

Downers Grove, Ill., assignors to Symons Mfg., Company, Des Plaines, 111., a corporation of Delaware Filed May 27, 1964, Ser. No. 370,513 4 Claims. (Cl. 249-48) The present invention relates to a flexible panel which is adapted when positioned in edge-to-edge relationship with like or similar panels to form a useful assembly or composite unit. A wide variety of uses are contemplated for the flexible panel of the present invention, one important use being as a concrete form panel for use in the formation or construction of a cylindrical concrete column. pipe section. These two uses have been selected as exemplary uses and, accordingly, each is illustrated in the accompanying drawings and described herein in detail. Other uses, however, will be pointed out briefly and further uses will readily suggest themselves when the nature of the invention i better understood.

Briefly, the flexible panel of the present invention is formed of a metal or other material (plastic) which readily lends itself to an extrusion process in connection with its fabrication. An example of a suitable metal is magnesium, which, when extruded, can maintain such detailed shapes as sharp corners, edges and the like and requires no further machining or other operations to create such shapes. The panel is preferably formed from a long extrusion so that it may be cut to any selected or desired length. The side edges of the panel are shaped for interlocking engagement with the side edges of adjacent like or similar associated panels in any given installation or use, one side edge being shaped to provide a Another important use for the panel is as a culvert particular male interlock and the other side edge being shaped to provide a particular female interlock. Since the panel is both flexible and resilient, it may be joined in edge-to-edge relationship with like panels and the entire assembly of thus joined panels bent to various desired curvatures. If all adjacent panels of a given assembly of panels are interlocked,. there results a closed tubular structure which may be cylindrical, elliptical, or otherwise curved. The length of the composite tubular struc ture is, of course, determined by or dependent upon the cut-off length of the individual panels or sections.

When a cylindrical concrete column form is formed by an annular series of panels embodying the present invention, because all adjacent panels are interlocked along their abutting or meeting edges and also because the concrete, after hardening, precludes any disconnection or unlocking of such meeting edges, at least two adjacent panels are provided with bolt-equipped flanges which may easily be separated when a form-dismantling operation is required.

An important feature of the present invention is predicated upon the fact that concrete building columns are usually specified for diameters which are multiples of one inch. Thus, for each progressively larger diameter column, the circumference of the column is increased by 3.1416 inches, or in other words, by 1 pi inches, where pi represents the ratio of the circumference of a circle to its diameter. According to the present invention, the flexible extruded panels are furnished in widths which are multiples of 1 pi inches.

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Practical considerations relating mainly to the cost of the extruding dies preclude the use of panels which are wider than 3 pi inches at the most, 1 pi and 2 pi inch wide panels being preferable. With an inventory or stock consisting of only panels having a width of 1 pi inches, any specified standard diameter concrete column may be accommodated; The use of panels which are 2 pi or 3 pi inches in width may be resorted to in order to reduce the number of interlocking joints between adjacent panels. With an inventory of only 2 pi inch width panels, obviously only columns having diameters which are multiples of two inches may be accommodated. However, with a mixed inventory which need include only one 1 pi or one 3 pi inch Width panel, practically all standard specified concrete columns or similar structures may be accommodated.

Specifications for culvert pipe similarly dictate that the diameter of the pipe be in increments of two inches from the smallest six-inch diameter culvert pipe up to twelve inches. Thereafter, and up to four feet, the increments of increase in culvert pipe diameter are usually three inches. From four feet to eight feet, the increment of increase in pipe diameter are six inches. The extruded panel of the present invention is usable substantially without modification either as a concrete column form panel or as a culvert pipe panel or section. Thus, the 2 pi and 3 pi inch width panels in a mixed inventory as mentioned heretofore will accommodate practically all specified standard diameter culvert pipes. In the smallest range diameter culvert pipes, the use of 2 pi inch wide panels will accommodate all specified pipe diameters. In the medial range, as well as in the largest range, the use of 3 pi inch wide panels Will accommodate all specified pipe diameters. Obviously, in all three ranges, an appropriate combination of 2 pi and 3 pi inch wide panels will accommodate all specified pipe diameters.

Where the panels of the present invention are employed in the assembly of culvert or other pipe sections, it is unnecessary to provide bolt-equipped flanges between an adjacent pair of panels inasmuch as the assembly usually is a permanent one and requires no future dismantling operation.

Other uses for flexible extruded panels embodying the present invention include the construction of irregular shapes, such as harbor piers which have flat sides with semi-cylindrical end portions and the construction of circular swimming pools or pools or pits with curved ends.

Generally speaking, the principal object of the invention is to provide a flexible extruded panel which has many capabilities of use and is characterized by low cost and ease of fabrication, facility of assembly with similar panels and durability as well as a high strength-weight ratio.

Other objects of the invention and the various advantages and characteristics ofthe present flexible extruded panel will be apparent from a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by the claims at the conclusion hereof.

In the accompanying two sheets of drawings forming a part of this specification, two illustrative embodiments of the invention are shown.

In these drawings:

FIG. 1 is a fragmentary perspective view of a concrete column form employing a number of flexible extruded panels embodying the present invention;

FIG. 2 is an enlarged end. view of one of the panels of FIG. 1, the panel being shown in its free or unflexed state;

FIG. 3 is a view similar to FIG. 2, but showing a composite, separable, two-part or sectional panel;

FIG. 4 is a sectional view taken substantially on the horizontal plane indicated by the line 44 of FIG. 1 and in the direction of the arrows;

FIG. 5 is a fragmentary perspective view of a length of culvert pipe employing a number of the panels embodying the present invention;

FIG. 6 is an enlarged transverse sectional view taken on the line 6-6 of FIG. 5;

FIG. 7 is an enlarged end view of the culvert pipe structure that is shown in FIG. 5; and

FIG. 8 is a dimension chart illustrating certain panel Width considerations that .are involved in connection with the present invention.

Referring now to the drawings in detail, and in particular to FIGS. 1 and 4 wherein flexible extruded panels embodying the present invention are illustrated as constituting a concrete column form, the illustrated form embodies six of the improved panels, four of the six panels being one-piece panels and designated by the reference numeral 10, and the two other panels being twopart separable panels and designated by the reference numeral 12. One of the panels 10 is shown in detail in FIG. 2, while one of the two-part panels 12 is shown in detail in FIG. 3.

Referring now to FIG. 2, each panel 10 is in the form of an elongated narrow extruded sheet, preferably magnesium or suitable plastic material, and consists of a substantially flat, although slightly transversely arched or curved, medial portion 14. The latter is of uniform thickness throughout and embodies enlarged or thickened, full length, outwardly displaced side edge portions 16 and 18. The radius of the arch or curve of the medial portion 14 is relatively long and may be on the order of eighteen inches. The thickened edge portion 16 is shaped to provide a male interlock tongue portion 20 of goose-neck design and such tongue portion is expressly designed for interlocking engagement with the thickened edge portion 18 of an adjacent panel (see FIGS. 1 and 4) in any given installation, the latter edge portion affording a female interlock groove portion 22 of a complementary nature. The tongue portion 20 and the groove portion 22 are of a suitable dovetail design with the cross-sectional area of the tongue portion being somewhat smaller than that of the longitudinal groove of the groove portion 22 in order to facilitate assembly and separation or disconnection of the adjacent panel edges. The tongue portion 20 comprises an outer head-like part 20a and an inner neck-like part 20b. The enlarged head like part 20a is semi-circular in cross section and the neck-like part 20b is approximately half as wide as the head-like part and has its outer side portion connected to the medial portion of the flat side of said head-like part. The inner side portion of the.neck-'like part 20b of the tongue portion 20 is connected to the adjacent side edge portion of the panel 10 by an L-shaped connecting part 20c which extends outwardly and circumferentially with respect to the medial portion 14 and results in the outer head-like part 20a and the inner neck-like part 20b being outwardly offset with respect to the medial portion 14. The groove in the groove portion 22 embodies an enlarged inner part 22a which is of semi-circular cross section and receives slidably and loosely the outer head-like part 20a of the tongue 20 of the adjacent panel, and also embodies a narrow entrance part 22b which is adapted slidably and substantially snugly to receive the inner neck-like part 20b of the tongue portion 20 of the adjacent panel. As best shown in FIG. 6, the enlarged female side edge portion 18 is so designed that the female interlock groove portion 22 is, in its entirety, outwardly offset with respect to the inner side surface of the medial portion 14. In other words, the side edge portion 18 as well as the side edge portion 16 is thickened outwardly but not inwardly. Assembly of two adjacent panels is made by sliding the panels longitudinally relatively to one another and panel separation or disconnection is made in the same manner. An assembly of the male interlock tongue portion 20 and the female interlock groove portion 22 is shown in enlarged detail in FIG. 6.

More specifically, the enlarged female side edge portion 18 of each panel 10 present-s an elongated, full length, flat edge surface or shoulder 24 (see FIGS. 2, 3 and 6). The latter extends at right angles to the inner side surface of the medial portion 14. It is disposed inwards of the narrow entrance part 22b of the groove of the groove portion 22 and, when two adjacent panels are interlocked, abuts in sealing relationship against a narrow, full length, fiat mating edge surface or shoulder 26 on the thickened male side edge portion 16 of the adjacent panel. The shoulder 26 extends at right angles to the inner side surface of the medial portion 14 and is disposed inwards of the inner neck-like part 20b of the tongue portion 20. By reason of the particular manner in which the enlarged or thickened side edge portions 16 and 18 are formed, the inner side surfaces of the panels are smooth or uninterrupted and, consequently, the inner surfaces of the joints between adjacent panels are smooth or continuous with the result that there will be no appreciably visible vertical seam lines in the finished. concrete column.

The panels are flexible and somewhat resilient' so that after a number of them have been assembled in interlocked edge-to-edge relationship, the assembly of panels may be laterally flexed as a unit to the tubular form in which it is shown in FIG. 1 and a final interlock made to close the assembly and provide a tubular or cylindrical concrete column form. When thus flexed with care, uniform distribution of stresses automatically results in the form and the substantially coplanar interlock shoulders 30 which are formed on the inner flat sides of the outer head-like parts 20a of the tongue portions 20, are on opposite sides of the outer end portions of the comparatively narrow neck-like parts 20b, and engage or abut against corresponding substantially coplanar interlock shoulders 31 at the sides of the enlarged inner groove parts 22a in the thickened female side edge portions 18, place the tongue portions 20 under tension with the result that the shoulders 24 and 26 are drawn hard against each other and in sealing relationship, and thus, prevent egress of the wet poured concrete 32 from the closed concrete column form that is formed by the panels 10 and 12.

If only an annular series of the panels 10 were utilized to form the concrete column form of FIG. 1, it would be difiicult, if not impossible, after hardening of the concrete 32 to dismantle the form. Therefore, to facilitate such dismantling operation, it is contemplated that one or more of the two-part separable panels 12 will be employed in any given concrete column form assembly. As shown in FIG. 3, each two-part or composite panel 12 consists of two sections, namely, a male section 40 and a female section 42. Each of thest two sections has a laterally-turned, outwardly extending, bolting flange 44. flanges of the two sections 40 and 42 are normally positioned in abutting relation and are releasably secured together by nut and bolt assemblies 46. The male section 40 of each panel 12 is provided with an enlarged or thickened male side edge portion 16 embodying a male interlock tongue portion 20, while the female section 42 of each panel 12 is provided with an enlarged or thickened female side edge portion 18 embodying a female interlock groove portion 22. The two sections 40 and 42 have a combined width equal to the width of one of the panels 10 and, preferably but not necessarily, the widths of the two sections are equal.

It is to be noted that when the two sections 40 and 42 The bolting:

are bolted together, the inside face of the two-pait of composite panel 12 presents a smooth, substantially unbroken surface at the juncture region between panel sections to enhance the exterior appearance of the concrete column in the manner previously set forth in connection with the juncture regions between adjacent panels 10.

As shown in FIG. 4, in dotted lines, dismantling of a concrete column form which is formed by way of an annular series of the panels 10 and '12 is facilitated or made possible simply by unbolting the male and female sections 40 and 42 of either or both composite panels 12 and unwrapping the remaining interlocked panels from the hardened concrete column. Initial assembly of panels in a given concrete column form installation may be made with the panel sections 40 and 42 of the panels 12 preas- 'sembled or, if desired, the final assembly step may be made by bolting two male and female panel sections together.

In FIGS. and 7, five of the panels are shown as being assembled upon one another in an annular series to provide a section 50 of culvert pipe. The assembled panels 10 ordinarily require no dismantling and, therefore, it is not necessary to employ a two-part separable panel 12 where pipe forming operations are concerned. Assembly operations are precisely the same as that involved in connection with the construction of a concrete column form installation and, therefore, need not be again described.

In the case of the concrete column form installation of FIG. 1, the panels 10 and 12 may be cut to the desired length conformable with the height of the particular concrete column being erected. ,Similarly, in the case of the culvert pipe length of FIG. -5, the panels 10 may be cut to length.

According to the present invention, the one-piece panels 10 are manufactured so as to have a width of 1 pi inches or, roughly, three and one-seventh inches. The two-part separable panels 12 likewise are manufactured to have a width of 1 pi inches. Such panels 10 and 12, in quantity, will suffice for use in the erection of all specified standard concrete column diameters since for each one-inch increase in the width or diameter of a column, an additional panel will be added to the assembly. Thus, the six-panel concrete column form installation of FIG. 1 is designed for the erection of a six-inch diameter concrete column.

As shown in FIG. 8, a panel 110 may be constructed to have a width of 2 pi inches or, roughly, six and twosevenths inches. The addition of such a panel to any given concrete column form assembly will increase the form diameter by two inches. If desired, a panel such as the panel 210 of FIG. 8 may be provided, such panel having a panel width of 3 pi inches or, roughly, nine and three-sevenths inches. However, the relatively high cost of the extruding dies for making such a panel is to be given consideration. The addition of a panel like the 3 pi inch panel 210 will increase the diameter of the concrete column form by three inches.

It will be understood that the term panel width as employed herein does not refer to actual end-to-end linear panel width. Rather, it refers to over-all arc length of the various panels from the shoulder 24 to the shoulder 26 and excluding the width of the tongue portion 20.

It will also be understood that the panels 110 and 210 are substantially identical with the panel 10 except for the matter of the increased width thereof. This increased width is absorbed in the medial bowed or arcuate portions of the panels, the dimensions of the thickened side edge portions 16 and 18 embodying the male and female interlock tongue and groove portions 20 and 22 respectively remaining the same.

Referring now to FIGS. 5, 6 and 7, the panels 10, 110 and 210 are capable of being employed substantially without any modification whatsoever as panels of the culvert pipe assembly 50. Due to the fact that such an assembly, once eifected, is a permanent one, it is not necessary to employ a twopart or composite separable panel 12 as an element thereof. Since, as previously described, culvert pipe increases in diameter on an ascending scale in three ranges involving multiples of two, three and six inches, respectively, an appropriate inventory of different sizes for a culvert pipe contractor will include a number of panels and 210.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. Therefore, only insofar as the invention is particularly pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what we claim as new and desire to secure by Letters Patent is:

1. As a new article of manufacture, a closed tubular structure comprising a series of ordinarily substantially flat flexible and resilient panels disposed in interlocking and edge-to-edge relationship, each panel constituting an arcuate circumferential section of such structure, one side edge portion of each panel being outwardly but not inwardly thickened and presenting a wholly outwardly offset goose-neck tongue portion which has an appreciable circumferential direction of extent, leads the adjacent side edge of the panel, comprises an outer enlarged head-like part and an inner comparatively narrow neck-like part, and has on the inner side of the head-like part and on opposite sides of the outer end portion of the neck-like part a pair of substantially flat and coplanar interlock shoulders, the other side edge portion of each panel being outwardly but not inwardly thickened and presenting a wholly outwardly offset groove-equipped portion, said groove-equipped portion having formed therein a longitudinal groove which is in cross section shaped substantially conformably to the head-like and neck-like parts of the aforementioned goose-neck tongue portion, comprises an enlarged inner part for slidably receiving the outer enlarged head-like part of the goose-neck tongue portion of the adjacent panel and, in addition, a narrow outer entrance part for slidably receiving the neck-like part of the goose-neck tongue portion of the adjacent panel, and has at the sides of the enlarged inner part a pair of substantially flat and coplanar interlock shoulders for abutment against the interlock shoulders on the inner side of the head-like part of the goose-neck tongue portion of the adjacent panel, the goose-neck tongue portion of each panel being interlocked with the groove-equipped portion of the adjacent panel, the medial region of each panel between said goose-neck tongue portion and said groove-equipped portion being of substantially uniform thickness, the opposed meeting side edges of adjacent panels being provided with abutting reaction shoulders which are disposed radially inwards of the interlocked goose-neck tongue portions and the groove-equipped portions, the panels existing under circumferential flexion so that the goose-neck tongue portions are under tension, the interlock shoulders are maintained in firm abutting relation, and the abutting reaction shoulders are under compression in order to produce a sealed relationship.

2. A closed tubular structure according to claim 1 and wherein one of said panels is of a two-part sectional nature, split longitudinally along its medial region to provide meeting edges, said meeting edges being formed with radially outwardly turned flanges and having fastening bolts associated therewith for releasably maintaining the sections of the composite panel together in edge-to-edge relationship.

3. A closed tubular structure according to claim 1 and wherein the panels are of equal width and the effective circumferential extent of each panel is an even multiple of 1 pi inches, where pi represents the ratio of the circumference of a circle to its diameter.

4. A closed tubular structure according to claim 1 and wherein the outer enlarged head-like part of the goose- 7 8 neck tongue portion and the enlarged inner part of the 2,770,386 11/1956 Mitchell et a1 22076 groove in the groove-equipped portion are serni-circu1ar 2,861,277 11/1958 Hermann 22076 in cross section.

FOREIGN PATENTS References Cited by the Examiner 5 786,197 11/1957 Great Britain UNITED STATES PATENTS 443,704 12/1890 James 22 100 J. SPENCER OVERHOLSER, Primary Examiner.

1,300,381 4/ 1919 Gruenfeld et a1 249143 G. A. KAP, R. D. BALDWIN, Assistant Examiners. 

1. AS A NEW ARTICLE OF MANUFACTURE, A CLOSED TUBULAR STRUCTURE COMPRISING A SERIES OF ORDINARILY SUBSTANTIALLY FLAT FLEXIBLE AND RESILIENT PANELS DISPOSED IN INTERLOCKING AND EDGE-TO-EDGE RELATIONSHIP, EACH PANEL CONSTITUTING AN ARCUATE CIRCUMFERENTIAL SECTION OF SUCH STRUCTURE, ONE SIDE EDGE PORTION OF EACH PANEL BEING OUTWARDLY BUT NOT INWARDLY THICKENED AND PRESENTING A WHOLLY OUTWARDLY OFFSET GOOSE-NECK TONGUE PORTION WHICH HAS AN APPRECIABLE CIRCUMFERENTIAL DIRECTION OF EXTENT, LEADS THE ADJACENT SIDE EDGE OF THE PANEL, COMPRISES AN OUTER ENLARGED HEAD-LIKE PART AND AN INNER COMPARATIVELY NARROW NECK-LIKE PART, AND HAS ON THE INNER SIDE OF THE HEAD-LIKE PART AND ON OPPOSITE SIDES OF THE OUTER END PORTION OF THE NECK-LIKE PART A PAIR OF SUBSTANTIALLY FLAT AND COPLANAR INTERLOCK SHOULDERS, THE OTHER SIDE EDGE PORTION OF EACH PANEL BEING OUTWARDLY BUT NOT INWARDLY THICKENED AND PRESENTING A WHOLLY OUTWARDLY OFFSET GROOVE EQUIPPED PORTION, SAID GROOVE-EQUIPPED PORTION HAVING FORMED THEREIN A LONGITUDINAL GROOVE WHICH IS IN CROSS SECTION SHAPED SUBSTANTIALLY CONFORMABLY TO THE HEAD-LIKE AND NECK-LIKE PARTS OF THE AFOREMENTIONED GOOSE-NECK TONGUE PORTION, COMPRISES AN ENLARGED INNER PART FOR SLIDABLY RECEIVING THE OUTER ENLARGED INNER PART OF THE GOOSE-NECK TONGUE PORTION OF THE ADJACENT PANEL AND, IN ADDITION, A NARROW OUTER ENTRANCE PART FOR SLIDABLY RECEIVING THE NECK-LIKE PART OF THE GOOSE-NECK TONGUE PORTION OF THE ADJACENT PANEL, AND HAS AT THE SIDES OF THE ENLARGED INNER PART A PAIR OF SUBSTANTIALLY FLAT AND COPLANAR INTERLOCK SHOULDERS FOR ABUTMENT AGAINST THE INTERLOCK SHOULDERS ON THE INNER SIDE OF THE HEAD-LIKE PART OF THE GOOSE-NECK TONGUE PORTION OF THE ADJACENT PANEL, THE GOOSE-NECK TONGUE PORTION OF EACH PANEL BEING INTERLOCKED WITH THE GROOVE-EQUIPPED PORTION OF THE ADJACENT PANEL, THE MEDIAL REGION OF EACH PANEL BETWEEN SAID GOOSE-NECK TONGUE PORTION AND SAID GROOVE-EQUIPPED PORTION BEING OF SUBSTANTIALLY UNIFORM THICKNESS, THE OPPOSED MEETING SIDE EDGES OF ADJACENT PANELS BEING PROVIDED WITH ABUTTING REACTION SHOULDERS WHICH ARE DISPOSED RADIALLY INWARDS IF THE INTERLOCKED GOOSE-NECK TONGUE PORTIONS AND THE GROOVE-EQUIPPED PORTIONS, THE PANELS EXISTING UNDER CIRCUMFERENTIAL FLEXION SO THAT THE GOOSE-NECK TONGUE PORTIONS ARE UNDER TENSION, THE INTERLOCK SHOULDERS ARE MAINTAINED IN FIRM ABUTTING RELATION, AND THE ABUTTING REACTION SHOULDERS ARE UNDER COMPRESSION IN ORDER TO PRODUCE A SEALED RELATIONSHIP. 